Elastic laminated sheet of an incrementally stretched nonwoven fibrous web and elastomeric film and method

ABSTRACT

An elastic laminated sheet of an incrementally stretched nonwoven fibrous web and elastomeric film and method of making are disclosed. The elastic laminates are especially useful in diapers, surgical gowns, sheets, dressings, hygienic products and the like.

BACKGROUND OF THE INVENTION

Processes of bonding nonwoven fibrous webs to thermoplastic films havebeen known for some time. Additionally, methods for extrusion laminatingthermoplastic films to unstretched nonwoven webs are well known in theart.

Relevant patents regarding extrusion lamination of unstretched nonwovenwebs include U.S. Pat. Nos. 2,714,571; 3,058,863; 4,522,203; 4,614,679;4,692,368; 4,753,840 and 5,035,941. The above '863 and '368 patentsdisclose stretching extruded polymeric films prior to laminating withunstretched nonwoven fibrous webs at pressure roller nips. The '203 and'941 patents are directed to co-extruding multiple polymeric films withunstretched nonwoven webs at pressure roller nips. The '840 patentdiscloses preforming nonwoven polymeric fiber materials prior toextrusion laminating with films to improve bonding between the nonwovenfibers and films. More specifically, the '840 patent disclosesconventional embossing techniques to form densified and undensifiedareas in nonwoven base plies prior to extrusion lamination to improvebonding between nonwoven fibrous webs and films by means of thedensified fiber areas. The '941 patent also teaches that unstretchednonwoven webs that are extrusion laminated to single ply polymeric filmsare susceptible to pinholes caused by fibers extending generallyvertically from the plane of the fiber substrate and, accordingly, thispatent discloses using multiple co-extruded film plies to preventpinhole problems. Furthermore, methods for bonding loose nonwoven fibersto polymeric film are disclosed in U.S. Pat. Nos. 3,622,422; 4,379,192and 4,725,473.

It has also been known to stretch nonwoven fibrous webs usingintermeshing rollers to reduce basis weight and examples of patents inthis area are U.S. Pat. Nos. 4,153,664 and 4,517,714. The '664 patentdiscloses a method of incremental cross direction (CD) or machinedirection (MD) stretching nonwoven fibrous webs using a pair ofinterdigitating rollers to strengthen and soften nonwoven webs. The '664patent also discloses an alternative embodiment wherein the nonwovenfibrous web is laminated to the thermoplastic film prior to intermeshstretching.

There is a continuing need for improved laminates of nonwoven fibroussubstrates in plastic films that provide sufficient absorbency andsoftness. It would be very desirable to further improve the propertiesof such laminates and to expand their utilities in articles of clothingand other useful products. Improvements are also desirable in methods ofproducing such laminates on high speed production machinery.

SUMMARY OF THE INVENTION

This invention is directed to an elastic laminated sheet of a nonwovenfibrous web and an elastomeric film. The term "elastic" is used in thespecification and claims as meaning stretchable under force andrecoverable to its original or essentially original form upon release ofthat force. The fibrous web has a multitude of fibers extendingoutwardly from the laminated surface that are formed by incrementalstretching of the laminated sheet along lines substantially uniformlyacross the laminated sheet and throughout its depth. The laminatedelastomeric film is stretchable and recoverable to provide elasticity tothe laminated sheet.

This invention also provides a method for producing the elastic laminateon high speed production machinery at line speeds of about 500 fpm.Thus, this invention provides for laminates of nonwoven fibroussubstrates and elastomeric films that have sufficient absorbency andsoftness with new properties of stretchability and recoverability. Theunique laminates and properties enable the laminated sheet to be usedfor many purposes including particularly articles of clothing wherestretchability and recoverability are significant properties.

The elastic laminated sheet comprises a nonwoven fibrous web and anelastomeric film laminated to at least one web surface. The elastomericfilm may be on one side of the nonwoven or between the nonwovens to formthe elastic laminate. The laminate is incrementally stretched alonglines substantially uniformly across its length and width and throughoutits depth to form a stretchable and recoverable composite. Thus,stretched zones may be separated or bordered by unstretched zones in thelaminate to provide elasticity to the laminate. Elasticity in thecomposite is mainly attributable to the elastic film. Under elongationor deformation forces, the laminate is stretchable and thus wouldconform, for example, to parts of the body when employed as a fabric inan article of clothing. Similarly, with the unique property of elasticrecovery, the laminate will essentially return to its original state.Furthermore, it may be repeatedly subjected to stretching and recovery.

In a most preferred form, the method of this invention involveslamination by extrusion or adhesion of the nonwoven fibrous web to theelastomeric film. Preferably the method may be conducted on high speedproduction machinery on the order of about 500 fpm. It involves inlinelamination and incremental stretching. More specifically, a nonwovenfibrous web is introduced into a nip of rollers for extrusion laminationwith an elastomeric film. An elastomeric extrudate is extruded into thenip at a temperature above its softening point to form a film laminatedto the fibrous web. The compressive force between the fibrous web andextrudate at the nip is controlled to bond one surface of the web to thefilm to form the laminate. As indicated above, the laminate or compositemay also be formed by adhesively bonding the fibrous web to theelastomeric film. The thus formed laminate is then incrementallystretched along lines substantially uniformly across the laminate andthroughout its depth to provide an elastic laminated sheet. By applyingan incremental stretching force to the laminated sheet, both the web andthe film are stretched. Upon removing the stretching force from thelaminated sheet, the elastic film recovers its shape and fibers of theweb are thereby caused to extend outwardly from the bonded web surfaceto give loft to the laminated sheet.

Other benefits, advantages and objectives of this invention will befurther understood with reference to the following detailed description.

DETAILED DESCRIPTION

It is a primary objective of this invention to produce an elasticlaminated sheet of a nonwoven fibrous web and an elastomeric film onhigh speed production machinery to produce recoverable and stretchablelaminates. It is a further objective to produce such laminates havingsatisfactory bond strengths while maintaining the appearance of fabricand soft feel. As developed above, these and other objectives areachieved in preferred form of the invention by first incrementallystretching a laminated sheet of nonwoven fibrous web and elastomericfilm along lines substantially uniformly across the laminate andthroughout its depth. It has been found, by incrementally stretching thelaminate, that an elastic sheet material is produced where the fibrousweb is bonded to the elastomeric film, yet the sheet is stretchable andrecoverable to essentially its original state. Furthermore, it has beenfound that such a laminated composite may be made by extrusion andstretching inline in order to achieve production speeds on the order ofabout 500 fpm. The elastic laminate in one form is characterized bybeing impervious to the passage of fluid by virtue of the elastomericfilm while maintaining a soft feel on the fibrous web surface of thelaminate. Alternatively, various degrees of vapor or air permeabilitymay be achieved in the laminate or composite by providing mechanicalmicrovoids, for instance. In a preferred form, the elastic laminate ofthis invention has the desirable feature of soft feel to achieve utilityin a number of applications including diapers, pants, surgical gowns,sheets, dressings, hygienic products and the like.

A. Materials for the Laminate

The elastomeric film preferably is of the polyolefin type that isprocessable into a film for direct lamination by melt extrusion onto thefibrous web in one embodiment. Suitable elastomeric polymers may also bebiodegradable or environmentally degradable. Suitable elastomericpolymers for the film include poly(ethylene-butene),poly(ethylene-hexene), poly(ethylene-octene),poly(ethylene-propylene),poly(styrene-butadiene-styrene),poly(styrene-isoprene-styrene), poly(styrene-ethylene-butylene-styrene),poly(ester-ether), poly(ether-amide), poly(ethylene-vinylacetate),poly(ethylene-methylacrylate), poly(ethylene-acrylic acid),poly(ethylene butylacrylate), polyurethane,poly(ethylene-propylene-diene), ethylene-propylene rubber. A new classof rubber-like polymers may also be employed and they are generallyreferred to herein as polyolefins produced from single-cite catalysts.The most preferred catalysts are known in the art as metallocenecatalysts whereby ethylene, propylene, styrene and other olefins may bepolymerized with butene, hexene, octene, etc., to provide elastomerssuitable for use in accordance with the principles of this invention,such as poly(ethylene-butene), poly(ethylene-hexene),poly(ethylene-octene), poly(ethylene-propylene) and/or polyolefinterpolymers thereof.

The nonwoven fibrous web may comprise fibers of polyethylene,polypropylene, polyesters, rayon, cellulose, nylon, and blends of suchfibers. A number of definitions have been proposed for nonwoven fibrouswebs. The fibers are usually staple fibers or continuous filaments. Asused herein "nonwoven fibrous web" is used in its generic sense todefine a generally planar structure that is relatively flat, flexibleand porous, and is composed of staple fibers or continuous filaments.For a detailed description of nonwovens, see "Nonwoven Fabric Primer andReference Sampler" by E. A. Vaughn, Association of the Nonwoven FabricsIndustry, 3d Edition (1992). The nonwovens may be carded, spun bonded,wet laid, air laid and melt blown as such products are well known in thetrade.

In a preferred form, the elastic laminated sheet employs an elastomericfilm having a gauge or a thickness between about 0.25 and 10 mls and,depending upon use, the film thickness will vary and, most preferably,in disposable applications is the order of about 0.25 to 2 mils inthickness. The nonwoven fibrous webs of the laminated sheet normallyhave a weight of about 10 grams per square yard to 60 grams per squareyard preferably about 20 to about 40 grams per square yard. Whenemploying adhesive lamination, adhesives such as hot melt adhesive,water base adhesive or solid base adhesive may be used. The composite orlaminate can be incrementally stretched in the cross direction (CD) toform a CD stretchable and recoverable composite. Furthermore, CDstretching may be followed by stretching in the machine direction (MD)to form a composite which is stretchable and recoverable in both CD andMD directions. As indicated above, the composite or laminate may be usedin many different applications such as baby diapers, baby trainingpants, catamenial pads and garments, and the like where stretchable andrecoverable properties, as well as fluid barrier properties are needed.

B. Stretchers For the Laminates

A number of different stretchers and techniques may be employed tostretch the starting or original laminate of a nonwoven fibrous web andelastomeric film. Laminates of nonwoven carded fibrous webs of staplefibers or nonwoven spun-bonded fibrous webs may be stretched with thestretchers and techniques described as follows:

1. Diagonal Intermeshing Stretcher

The diagonal intermeshing stretcher consists of a pair of left hand andright hand helical gear-like elements on parallel shafts. The shafts aredisposed between two machine side plates, the lower shaft being locatedin fixed bearings and the upper shaft being located in bearings invertically slidable members. The slidable members are adjustable in thevertical direction by wedge shaped elements operable by adjustingscrews. Screwing the wedges out or in will move the vertically slidablemember respectively down or up to further engage or disengage thegear-like teeth of the upper intermeshing roll with the lowerintermeshing roll. Micrometers mounted to the side frames are operableto indicate the depth of engagement of the teeth of the intermeshingroll.

Air cylinders are employed to hold the slidable members in their lowerengaged position firmly against the adjusting wedges to oppose theupward force exerted by the material being stretched. These cylindersmay also be retracted to disengage the upper and lower intermeshingrolls from each other for purposes of threading material through theintermeshing equipment or in conjunction with a safety circuit whichwould open all the machine nip points when activated.

A drive means is typically utilized to drive the stationery intermeshingroll. If the upper intermeshing roll is to be disengageable for purposesof machine threading or safety, it is preferable to use an antibacklashgearing arrangement between the upper and lower intermeshing rolls toassure that upon reengagement the teeth of one intermeshing roll alwaysfall between the teeth of the other intermeshing roll and potentiallydamaging physical contact between addendums of intermeshing teeth isavoided. If the intermeshing rolls are to remain in constant engagement,the upper intermeshing roll typically need not be driven. Drive may beaccomplished by the driven intermeshing roll through the material beingstretched.

The intermeshing rolls closely resemble fine pitch helical gears. In thepreferred embodiment, the rolls have 5.935" diameter, 45° helix angle, a0.100" normal pitch, 30 diametral pitch, 141/2° pressure angle, and arebasically a long addendum topped gear. This produces a narrow, deeptooth profile which allows up to about 0.090" of intermeshing engagementand about 0.005" clearance on the sides of the tooth for materialthickness. The teeth are not designed to transmit rotational torque anddo not contact metal-to-metal in normal intermeshing stretchingoperation.

2. Cross Direction Intermeshing Stretcher

The CD intermeshing stretching equipment is identical to the diagonalintermeshing stretcher with differences in the design of theintermeshing rolls and other minor areas noted below. Since the CDintermeshing elements are capable of large engagement depths, it isimportant that the equipment incorporate a means of causing the shaftsof the two intermeshing rolls to remain parallel when the top shaft israising or lowering. This is necessary to assure that the teeth of oneintermeshing roll always fall between the teeth of the otherintermeshing roll and potentially damaging physical contact betweenintermeshing teeth is avoided. This parallel motion is assured by a rackand gear arrangement wherein a stationary gear rack is attached to eachside frame in juxtaposition to the vertically slidable members. A shafttraverses the side frames and operates in a bearing in each of thevertically slidable members. A gear resides on each end of this shaftand operates in engagement with the racks to produce the desiredparallel motion.

The drive for the CD intermeshing stretcher must operate both upper andlower intermeshing rolls except in the case of intermeshing stretchingof materials with a relatively high coefficient of friction. The driveneed not be antibacklash, however, because a small amount of machinedirection misalignment or drive slippage will cause no problem. Thereason for this will become evident with a description of the CDintermeshing elements.

The CD intermeshing elements are machined from solid material but canbest be described as an alternating stack of two different diameterdisks. In the preferred embodiment, the intermeshing disks would be 6"in diameter, 0.031" thick, and have a full radius on their edge. Thespacer disks separating the intermeshing disks would be 51/2" indiameter and 0.069" in thickness. Two rolls of this configuration wouldbe able to be intermeshed up to 0.231" leaving 0.019" clearance formaterial on all sides. As with the diagonal intermeshing stretcher, thisCD intermeshing element configuration would have a 0.100" pitch.

3. Machine Direction Intermeshing Stretcher

The MD intermeshing stretching equipment is identical to the diagonalintermeshing stretch except for the design of the intermeshing rolls.The MD intermeshing rolls closely resemble fine pitch spur gears. In thepreferred embodiment, the rolls have a 5.933" diameter, 0.100" pitch, 30Diametral pitch, 141/2° pressure angle, and are basically a longaddendum, topped gear. A second pass was taken on these rolls with thegear hob offset 0.010" to provide a narrowed tooth with more clearance.With about 0.090" of engagement, this configuration will have about0.010" clearance on the sides for material thickness.

4. Incremental Stretching Technique

The above described diagonal, CD or MD intermeshing stretchers may beemployed to produce the incrementally stretched laminate of nonwovenfibrous web and elastomeric film of this invention. The stretchingoperation is usually employed on an extrusion laminate of a nonwovenfibrous web of staple fibers or spun-bonded filaments and elastomericfilm. In one of the unique aspects of this invention an elastic laminateof a nonwoven fibrous web of spun-bonded filaments may be incrementallystretched to provide a very soft fibrous finish to the laminate thatlooks like carded fibers with superior bond strengths. The laminate ofwoven fibrous web and elastomeric film is incrementally stretched using,for instance, the CD intermeshing stretcher with one pass through thestretcher with a depth of roller engagement at about 0.090 inch to 0.120inch at speeds from about 500 fpm to 1000 fpm or faster. The results ofsuch CD incremental or intermesh stretching produces laminates orcomposites that have excellent stretchability and recoverability and yetprovide superior bond strengths and soft fibrous textures.

DETAILED EXAMPLES OF THE INVENTION

The following examples illustrate the elastic laminates of thisinvention and methods of making them. In light of these examples andthis further detailed description, it is apparent to a person ofordinary skill in the art that variations thereof may be made withoutdeparting from the scope of this invention.

The invention is further understood with reference to the drawings inwhich:

FIG. 1 is a schematic of an inline extrusion lamination and incrementalstretching apparatus for making the laminate of this invention.

FIG. 2 is a cross sectional view taken along the line 2--2 of FIG. 1illustrating the intermeshing rollers in diagrammatic form.

FIG. 3 is a magnified diagrammatic sketch in cross-section of a nonwovenfibrous web laminated to the elastomeric film before stretching.

FIG. 4 is a magnified diagrammatic sketch of the laminate of FIG. 3after incremental stretching to provide a composite where the fibers ofthe web are caused to extend outwardly from the surface to give highloft to the laminated sheet that is stretchable and recoverableaccording to the principles of this invention.

FIG. 5 is a graph demonstrating the elongation properties of comparativeexamples.

FIG. 6 is a graph demonstrating the elongation properties of elasticlaminated sheets of this invention for comparison with comparativeextrusion laminated composites.

Comparative Examples I-1 and II-2

Extrusion lamination of low density polyethylene (LDPE) film to anonwoven fibrous web was made for direct comparison with an elasticextrusion laminate that was incrementally stretched according to thisinvention.

I-1. Extrusion Laminate of Nonwoven Fibrous Web and Thermoplastic Film(Without Incremental Stretching)

Two carded polypropylene nonwoven fibrous webs of 26 grams/yd² weightwere laminated by extrusion of a LDPE thermoplastic film with a densityof 0.914 g/cc at one mil between the webs according to the comparativeextrusion lamination technique as shown in the extrusion laminationsection of FIG. 1. As shown schematically in FIG. 1, the incoming webs9,9 from rollers 13, 13 were introduced into the nip of a rubber roll 5and a metal roll 4. The LDPE film 3 from extruder 1 was extruded throughdie 2 into the nip while the two carded fibrous webs 9,9 wereintroduced. Typically, at speeds over 500 fpm in this extrusionlamination section, the polyethylene film 3 on the order of about 0.25to 10 mils in thickness is laminated at melt temperatures on the orderof about 500°-625° F. to form the laminate 12 which is taken off atroller 7. The compressive force at the nip is controlled such that thewebs are bonded to the polyolefin film to avoid pinholing and preservethe fibrous feel on the fiber surfaces of the laminate 12. Pressures onthe order of about 10 to 80 psi are sufficient to achieve satisfactorybond for fibrous webs of about 10 to 60 grams/yd². In this example, thelaminate is tested for its stretchability using an Instron TensileTester. A one inch strip cut along its cross machine direction (CD) isstretched at 20"/min. This composite breaks at 45% elongation with anultimate tensile strength (broken strength) of 3.4 pounds per inch. Thiscomposite is not a stretchable and recoverable composite upon stretchingand releasing of the stretch force. This is demonstrated in FIG. 5,(Comparative Example I-1).

I-2. Extrusion Laminate of Nonwoven Fibrous Web and Thermoplastic FilmWith Incremental Stretching

When the Composite of Comparative Example I-1 is incrementally stretchedwith reference to the incremental stretched section Of FIG. 1, thecomposite can then be stretched to more than 50% elongation. Thestretching operation is schematically shown where the incoming web 12was passed through the CD stretcher rollers 10 and 11 at a depth ofroller engagement at about 0.100 inch at about 500 fpm. The intermeshingrollers 10 and 11 are diagrammatically shown in FIG. 2 to illustrate theuniform stretching along lines across the laminate and through the depthof the laminate. The elastic property of the modified composite is thentested according to its stress (tensile force) and strain (elongation)by using an Instron Tensile Tester (see FIG. 5, Example I-2). Thepermanent set of this modified composite when stretched to 50% is 20%(see FIG. 5, Example I-2). "Permanent set" means the final unrecoverabledimension of the composite after being stretched. This non-elasticlaminate is not a satisfactory stretchable and recoverable composite.

EXAMPLE II Elastic Laminate of Incrementally Stretched Nonwoven FibrousWeb and Elastomeric Film

In this Example the same procedures are followed as for Example I,except the plastic used in extrusion lamination was DOW Chemical'selastomeric incite resin XU 51800.51 with a density of 0.870 grams percubic centimeter. This new elastomeric resin is manufactured by usingethylene and octene comonomer with a new metallocene catalyst.

The elastic laminate made in this Example, when CD incrementallystretched using an engagement of 0.100" is soft, stretchable andrecoverable when compared to the laminate made according to Example I-1,except having a density of 0.870 g/cc. Table 1 and FIG. 6 show thedetailed differences. The permanent set of the Example I-1 whenstretched to 50% (FIG. 6, dotted curve 1), 75% (FIG. 6, dotted curve2)), and 100% (FIG. 6, dotted curve 3) are 10%, 26% and 38%,respectively. However the laminate becomes much softer and elasticaccording to this invention under less force when stretched to 50% (FIG.6, solid curve 4), 75% (FIG. 6, solid curve 5) and 100% (FIG. 6, solidcurve 6) are 6%, 18% and 24%, respectively. In its most preferred form,the permanent set of the laminate is no more than about 10% of itsoriginal dimension after first stretching to about 50% of its originalshape.

The force required to stretch the laminate of Example II according tothis invention is less than the comparative laminate (see Table 1). Therecovery after releasing the force upon stretching is higher (or thepermanent set is lower) with the laminate of this invention whencompared to the comparative laminate. The product according to thisinvention will be suitable for diaper application such as the trainingpant or elastic waist and leg where the recoverable elastic sheet isneeded.

The high loft of the stretched elastic laminate is diagrammaticallyshown (FIG. 4) with reference to one side of the laminate beforestretching (FIG. 3). The elastomeric film 3 is bonded to the surfacefibers 20 of the web 9 in the extrusion lamination section of FIG. 1. Toproduce a laminate 12 where only one side is diagrammatically shown inFIG. 3. After incremental stretching, the fibers of the web 9 are causedto extend outwardly and provide a high loft of fibers to the laminate 13as diagrammatically shown on one side in FIG. 4. The elastomeric filmrecovers its original or substantially original shape after stretching,whereas the web after stretching will increase in thickness andsoftness. This is one of the unique features of the laminate and methodof this invention.

                  TABLE 1                                                         ______________________________________                                                               LAMINATE                                                          COMPARATIVE OF THIS                                                           LAMINATE    INVENTION                                              ______________________________________                                        TOTAL        68            56                                                 COMPOSITE                                                                     WEIGHT                                                                        (G/YD.sup.2)                                                                  BOND         TOTAL BOND    TOTAL BOND                                         STRENGTH                                                                      (G/IN)                                                                        STRETCHED TO 50     75     100   50   75   100                                AN ELONGATION                                                                 SPECIFIED (%)                                                                 FORCE REQUIRED                                                                             1.75   2.05   2.10  0.9  1.45 1.90                               TO STRETCH TO                                                                 THE SPECIFIED                                                                 ELONGATION                                                                    (LBS/IN)                                                                      PERMANENT SET                                                                              10     26     38    6    18   24                                 AFTER THE                                                                     STRETCHING TO                                                                 THE SPECIFIED                                                                 ELONGATION (%)                                                                TENSILE      0.90   0.85   0.75  0.15 0.15 0.15                               STRENGTH AT                                                                   10% ELONGATION                                                                (LBS/IN)                                                                      ______________________________________                                    

Example III

Two 34 grams per square yard of carded polypropylene nonwoven areextrusion laminated to an elastomeric film by using an elastomeric blendof styrene-butadiene-styrene block copolymer and EVA copolymer. Themiddle layer of the elastomeric film is at 2.0 mils. The composite soproduced is then CD incrementally stretched by using an engagement of0.100". The incrementally stretched laminate according to this inventionbecomes more stretchable and recoverable upon stretching and releasingof the force when compared to the comparative laminate of the above sameelastomer composition without stretching. The force required to stretchthe composite according to the invention is also lower. The results areshown in Table 2.

                  TABLE 2                                                         ______________________________________                                                  COMPARATIVE LAMINATE OF                                                       LAMINATE    THIS INVENTION                                          ______________________________________                                        Stretch to an elon-                                                                       50     75     100   50    75   100                                gation specified at                                                           (%)                                                                           Force required to                                                                         1.25   2.0    2.4   0.25  0.35 0.45                               stretch to the speci-                                                         fied elongation                                                               (lbs/in)                                                                      Permanent set after                                                                       15     20     26    6     10   12                                 stretching force is                                                           released (%)                                                                  ______________________________________                                    

Example IV

A 41 grams per square yard carded polypropylene nonwoven is extrusionlaminated by using an EPDM elastomer. This laminate is then CDincrementally stretched with a CD stretcher engagement of 0.100". Thelaminate becomes soft, stretchable and recoverable upon stretching andreleasing of the stretch force and may be compared to the comparativelaminate of same composition without incremental stretching as shown inthe test results of Table 3.

                  TABLE 3                                                         ______________________________________                                                  COMPARATIVE LAMINATE OF                                                       LAMINATE    THIS INVENTION                                          ______________________________________                                        Stretch to an elon-                                                                       50     75     100   50    75   100                                gation specified at                                                           (%)                                                                           Force required to                                                                         1.2    1.5    1.6   0.5   0.7  0.9                                stretch to the speci-                                                         fied elongation                                                               (lbs/in)                                                                      Permanent set after                                                                       10     18     24    9     15   17                                 stretching force is                                                           released (%)                                                                  ______________________________________                                    

Example V

A Scot carded polypropylene nonwoven with 30 grams per square yard and2.0 mils of EPDM film is adhesively laminated by using an H. P. Fuller'sEVA hot melt adhesive 2835. This laminated sheet is then incrementallystretched by using the CD stretcher at 0.100" engagement to produce asoft and elastic sheet. A comparative laminate of the same compositionwithout incremental stretching was also run. Table 4 shows the testresults.

                  TABLE 4                                                         ______________________________________                                                  COMPARATIVE LAMINATE OF                                                       LAMINATE    THIS INVENTION                                          ______________________________________                                        Stretch to an elon-                                                                       50     75     100   50    75   100                                gation specified at                                                           (%)                                                                           Force required to                                                                         2.2    2.6    2.8   0.9   1.5  2.0                                stretch to the speci-                                                         fied elongation                                                               (lbs/in)                                                                      Permanent set after                                                                       8      19     25    6     14   18                                 stretching force is                                                           released (%)                                                                  ______________________________________                                    

Example VI

A DuPont sontara polyester fabric grade 8000 is extrusion laminated toDuPont polyester elastomer (Hytrel 8206) at 1.0 mil, The laminated sheetis then CD incrementally stretched by a CD incremental stretcher with anengagement of 0.100" to produce a soft, elastic, stretchable andrecoverable composite. A comparative laminate of the same compositionwithout incremental stretching was also run. Table 5 shows the testresults.

                  TABLE 5                                                         ______________________________________                                                  COMPARATIVE LAMINATE OF                                                       LAMINATE    THIS INVENTION                                          ______________________________________                                        Stretch to an elon-                                                                       50     75     100   50    75   100                                gation specified at                                                           (%)                                                                           Force required to                                                                         1.6    2.2    3.0   0.7   0.8  1.1                                stretch to the speci-                                                         fied elongation                                                               (lbs/in)                                                                      Permanent set after                                                                       18     32     42    8     17   23                                 stretching force is                                                           released (%)                                                                  ______________________________________                                    

Example VII

A DuPont Sontara polyester fabric grade 8000 is adhesive laminated toDuPont hytrel 8206 at 1.0 mil by using H. B. Fuller EVA hot meltadhesive 2835. The adhesive laminated sheet is then CD incrementallystretched by using a CD engagement of 0.08" followed with a MDstretching by using an engagement also of 0.08". The laminate is both aCD and MD stretchable and recoverable elastic composite. A comparativelaminate of the same composition without incremental stretching was alsorun. The test results are shown on Table 6.

                                      TABLE 6                                     __________________________________________________________________________                 COMPARATIVE LAMINATE                                                                            LAMINATE OF THIS INVENTION                     __________________________________________________________________________    Stretch to an elongation                                                                   50%   75%   100%  50%   75%    100%                              specified at (%)                                                              Direction    MD CD MD CD MD CD MD CD MD CD  MD CD                             Force required to stretch                                                                  NA*                                                                              2.2                                                                              NA*                                                                              3.5                                                                              NA*                                                                              5.0                                                                              0.8                                                                              0.7                                                                              1.1                                                                              1.0 1.3                                                                              1.1                            to the specified elongation                                                   (lbs/in)                                                                      Permanent set after                                                                        NA*                                                                              16 NA*                                                                              25 NA*                                                                              30 10 7  20 17  22 20                             stretching                                                                    __________________________________________________________________________     *NA  the material broke at 45% elongation                                

Example VIII

Exxon's Exact polymer type 4011 of ethylene and octene manufactured byusing a Metallocene catalyst at a density of 0.885 g/cc extrusionlaminated to DuPont's polyester sontara fabric grade 8000.

This extrusion laminated sheet is then CD incrementally stretched withan engagement of 0.090" followed with MD incremental stretching with anengagement of 0.065". The laminate is both CD and MD stretchable andrecoverable. A comparative laminate of the same composition withoutincremental stretching was also run. Table 7 shows the test results.

                                      TABLE 7                                     __________________________________________________________________________                 COMPARATIVE LAMINATE LAMINATE OF THIS INVENTION                  __________________________________________________________________________    Stretch to an elongation                                                                   50%    75%    100%   50%     75%    100%                         specified at (%)                                                              Direction    MD CD  MD CD  MD CD  MD  CD  MD  CD MD  CD                       Force required to stretch                                                                  NA*                                                                              1.35                                                                              NA*                                                                              1.75                                                                              NA*                                                                              2.40                                                                              0.75                                                                              0.75                                                                              1.05                                                                              0.9                                                                              1.25                                                                              1.05                     to the specified elongation                                                   (lbs/in)                                                                      Permanent set after                                                                        NA*                                                                              15  NA*                                                                              34  NA*                                                                              47  10  10  20  20 26  30                       stretching                                                                    __________________________________________________________________________     *NA  the material broke at 45% elongation                                

The above data and experimental results demonstrate the uniquestretchable and recoverable properties of the elastic laminated sheetsof this invention. Other variations will be apparent to a person ofskill in the art without departing from this invention.

What is claimed is:
 1. An elastic laminated sheet of a nonwoven fibrousweb and an elastomeric film comprisingan elastomeric film and a nonwovenfibrous web laminated to a surface of said film to form said laminatedsheet, said laminated sheet having a multitude of fibers extendingoutwardly from said laminated surface, said fibers being formed byincremental stretching of the laminated sheet along lines substantiallyuniformly across the laminated sheet and throughout its depth, saidlaminated sheet being stretchable and recoverable, having a permanentset after being stretched to 50% of its original shape of no more thanabout 10%.
 2. The elastic laminated sheet of claim 1 formed by extrusionor adhesive lamination.
 3. The elastic laminated sheet of claim 1wherein said fibrous web comprises fibers selected from the groupconsisting of polypropylene, polyethylene, polyester, cellulose, rayon,nylon and blends of two or more of such fibers.
 4. The elastic laminatedsheet of claim 1 wherein the polymer of said elastomeric film isselected from the group consisting of poly(ethylene-butene),poly(ethylene-hexene), poly(ethylene-octene), poly(ethylene-propylene),poly(styrene-butadiene-styrene), poly(styrene-isoprene-styrene),poly(styrene-ethylene-butylene-styrene), poly(ester-ether),poly(ether-amide), poly(ethylene-vinylacetate),poly(ethylene-methylacrylate), poly(ethylene-acrylic acid),poly(ethylene butylacrylate), polyurethane,poly(ethylene-propylene-diene), and ethylene-propylene rubber.
 5. Theelastic laminated sheet of claim 1 wherein said film has a thickness onthe order of about 0.25 to about 10 mils.
 6. The elastic laminated sheetof claim 1 wherein said nonwoven fibrous web has a weight of about 10grams/square yard to about 60 grams/square yard.
 7. The elasticlaminated sheet of claim 1 wherein said elastomeric film has a thicknesson the order of about 0.25 to about 2 mils and the nonwoven fibrous webhas a weight on the order of about 20 to about 40 grams/square yard. 8.The elastic laminated sheet of claim 1 incrementally stretched in across direction to form a stretchable and recoverable composite in saidcross direction.
 9. The elastic laminated sheet of claim 1 incrementallystretched in both its cross direction and longitudinal direction to forma stretchable and recoverable composite which is stretchable andrecoverable in both said cross and longitudinal directions.
 10. Theelastic laminated sheet of claim 1 wherein said elastomeric film hasopposite surfaces and a nonwoven fibrous web is laminated to bothsurfaces to provide said laminated sheet.
 11. The elastic laminatedsheet of claim 1 wherein the polymer of said elastomeric film is apolyolefin polymer produced by a reaction conducted in the presence of asingle site catalyst.
 12. The elastic laminated sheet of claim 11wherein the polyolefin is derived from the polymerization of monomersselected from the group consisting of ethylene, propylene, styrene,butene, hexene and octene, and mixtures thereof.